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At least 469 records · Page 26Linked to original sources
USGS1999

Restoring marsh elevation in a rapidly subsiding salt marsh by thin-layer deposition of dredged material

Thin-layer deposition of dredged material on coastal marsh by means of high-pressure spray dredging (Jet-Spray??2) technology has been proposed as a mechanism to minimize wetland impacts associated with traditional bucket dredging technologies and to restore soil elevations in deteriorated marshes of the Mississippi River delta. The impact of spray dredging on vegetated marsh and adjacent shallow-water habitat (formerly vegetated marsh that deteriorated to open water) was evaluated in a 0.5-ha Spartina alterniflora-dominated salt marsh in coastal Louisiana. The thickness of dredged sediment deposits was determined from artificial soil marker horizons and soil elevation change was determined from sedimentation-erosion tables (SET) established prior to spraying in both sprayed and reference marshes. The vertical accretion and elevation change measurements were made simultaneously to allow for calculation of shallow (~5 m depth) subsidence (accretion minus elevation change). Measurements made immediately following spraying in July 1996 revealed that stems of S. alterniflora were knocked down by the force of the spray and covered with 23 mm of dredged material. Stems of S. alterniflora soon recovered, and by July 1997 the percent cover of S. alterniflora had increased three-fold over pre-project conditions. Thus, the layer of dredged material was thin enough to allow for survival of the S. alterniflora plants, with no subsequent colonization by plant species typical of higher marsh zones. By February 1998, 62 mm of vertical accretion accumulated at this site, and little indication of disturbance was noted. Although not statistically significant, soil elevation change was greater than accretion on average at both the spray and reference marshes, suggesting that subsurface expansion caused by increased root biomass production and/or pore water storage influence elevation in this marsh region. In the adjacent shallow water pond, 129 mm of sediment was deposited in July 1996 as a result of spraying, and despite initial shallow subsidence and continual erosion through February 1998, water bottom elevation was raised sufficiently to allow S. alterniflora to invade via rhizome growth from the adjacent marsh. Hence, thin-layer deposition of dredged material at this site was effective at restoring and maintaining marsh elevation after 1.5 years. However, if the open water sediment deposits are not soon completely stabilized via further vegetative colonization, erosion may eventually lower elevations to the level where emergent vegetation cannot persist.

Ecological Engineering↗
USGS1999

Experiences with information locator services

Over the last few years, governments and other organizations have been using new technologies to create networked Information Locator Services that help people find information resources. These services not only enhance access to information, but also are designed to support fundamental information policy principles. This article relates experiences in developing and promoting services interoperable with the Global Information Locator Service standard that has now been adopted and promoted in many forums worldwide. The article describes sample implementations and touches on the strategic choices made in public policy, standards, and technology. Ten recommendations are offered for successful implementation of an Information Locator Service.

Journal of Government Information↗
USGS2003

Application of artificial neural networks to complex groundwater management problems

As water quantity and quality problems become increasingly severe, accurate prediction and effective management of scarcer water resources will become critical. In this paper, the successful application of artificial neural network (ANN) technology is described for three types of groundwater prediction and management problems. In the first example, an ANN was trained with simulation data from a physically based numerical model to predict head (groundwater elevation) at locations of interest under variable pumping and climate conditions. The ANN achieved a high degree of predictive accuracy, and its derived state-transition equations were embedded into a multiobjective optimization formulation and solved to generate a trade-off curve depicting water supply in relation to contamination risk. In the second and third examples, ANNs were developed with real-world hydrologic and climate data for different hydrogeologic environments. For the second problem, an ANN was developed using data collected for a 5-year, 8-month period to predict heads in a multilayered surficial and limestone aquifer system under variable pumping, state, and climate conditions. Using weekly stress periods, the ANN substantially outperformed a well-calibrated numerical flow model for the 71-day validation period, and provided insights into the effects of climate and pumping on water levels. For the third problem, an ANN was developed with data collected automatically over a 6-week period to predict hourly heads in 11 high-capacity public supply wells tapping a semiconfined bedrock aquifer and subject to large well-interference effects. Using hourly stress periods, the ANN accurately predicted heads for 24-hour periods in all public supply wells. These test cases demonstrate that the ANN technology can solve a variety of complex groundwater management problems and overcome many of the problems and limitations associated with traditional physically based flow models.

Natural Resources Research↗
USGS2020

Modified GIC estimation using 3-D Earth conductivity

Geomagnetically induced currents (GICs) are quasi-direct current (DC) electric currents that flow in technological conductors during geomagnetic storms. Extreme GICs are hazardous to man-made infrastructure. GICs enter and exit the technological systems, such as the electric power grid, at grounding points, and their magnitudes depend on the currents that flow underground. They are, therefore, a function of the Earth's electrical conductivity, represented at ground level as Earth impedances, as well as the resistance parameters of the power network. Traditional GIC estimation practices are based on Earth impedances obtained from laterally homogeneous or piecewise layered-Earth models. We refer to these methods, collectively, as the 1-D approximation. However, GIC hazard mitigation can be improved with more accurate GIC modeling that takes the spatially heterogeneous Earth's conductivity into account. Here, we propose a modified approximation for GIC estimation that is very similar to the 1-D approximation but is instead derived from empirical 3-D Earth impedances. Our formulation sets up the computation of static, frequency-dependent power line telluric response functions, which, once computed, may be considered part of the power grid system model. These response functions may then be used for historical scenario analysis of GIC hazards and for simplified real-time, albeit approximate, GIC estimation in a power grid. This modest modification to the simpler local field formulation approach avoids real-time integration of geoelectric fields along power lines while taking the realistic 3-D Earth into account in a rigorous manner. Once implemented, the method provides a power grid operator with the benefits of convenience and computational speed for a first look real-time operational GIC hazard assessment. We estimate that the proposed modified 3-D GIC modeling approach produces GIC values that are well within 50% of those obtained with the full-scale power line integration of spatially variable geoelectric fields, for storms comparable in scale to the 2003 Halloween storm, all geological structures, and power lines located in the contiguous United States and other low- to middle-latitude regions.

Space Weather↗
USGS2023

Alerting the globe of consequential earthquakes

The primary ingredients on the hazard side of the equation include the rapid characterization of the earthquake source and quantifying the spatial distribution of the shaking, plus any secondary hazards an earthquake may have triggered. On the earthquake impact side, loss calculations require the aforementioned hazard assessments—and their uncertainties—as input, plus the quantification of the exposure and vulnerability of structures, infrastructure, and the affected inhabitants. Lastly, effectively communicating uncertain estimates of the resulting impacts on society requires careful consideration of its function and form. All these aspects of rapid earthquake information delivery entailed wide-ranging collaborative research and development among seismologists, earthquake engineers, geographers, social scientists, Information Technology professionals, and communication experts, leveraging diverse components and ingredients not achievable without extensive collaboration. I was very fortunate to be able to work on interesting and useful projects with many colleagues who got involved with them. Advances in content, its rapid delivery, and our ability to better communicate uncertain loss estimates greatly expanded the range of users and critical decision-makers who could directly benefit from rapid post-earthquake information. Moreover, in the critical user–developer feedback loop, we have intently followed requests from users to develop new ways of delivering the most-requested post-earthquake information within the limitations of the science and technology. Such new avenues and tools then motivated and prioritized additional research directions and developments.

Perspectives of Earth and Space Scientists↗
USGS2023

Time-lapse seafloor surveys reveal how turbidity currents and internal tides in Monterey Canyon interact with the seabed at centimeter-scale

Here we show how ultra-high resolution seabed mapping using new technology can help to understand processes that sculpt submarine canyons. Time-lapse seafloor surveys were conducted in the axis of Monterey Canyon, ∼50 km from the canyon head (∼1,840 m water depth) over an 18-month period. These surveys comprised 5-cm resolution multibeam bathymetry, 1-cm resolution lidar bathymetry, and 2-mm resolution stereophotographic imagery. Bathymetry data reveal centimeter-scale textures that would be undetectable by more traditional survey methods. Upward-looking Acoustic Doppler Current Profilers at the site recorded the flow character of internal tides and the passage of three turbidity currents, while sediment cores collected from the site record flow deposits. Combined with flow and core data, the bathymetry shows how turbidity currents and internal tides modify the seabed. The turbidity currents drape sediment across the site, infilling bedform troughs and smoothing erosional features carved by the internal tides (e.g., rippled scours). Turbidity currents with speeds of 0.9–3.3 m/s failed to cause notable bedform movement, which is surprising given that flows with similar speeds produced rapid bedform migration elsewhere, including the upper Monterey Canyon. The lack of migration may be related to the character of the underlying substrate or indicate that turbidity currents at the site lack dense, near-bed layers. The scale of scours produced by the internal tides (≤0.7 m/s) approaches the scale of features recorded in the ancient rock record. Thus, these results illustrate how the scale gap between seabed mapping technology and the rock record may eventually be bridged.

California↗
USGS2010

Volcanic hazards and their mitigation: progress and problems

At the beginning of the twentieth century, volcanology began to emerge as a modern science as a result of increased interest in eruptive phenomena following some of the worst volcanic disasters in recorded history: Krakatau (Indonesia) in 1883 and Mont Pelée (Martinique), Soufrière (St. Vincent), and Santa María (Guatemala) in 1902. Volcanology is again experiencing a period of heightened public awareness and scientific growth in the 1980s, the worst period since 1902 in terms of volcanic disasters and crises. A review of hazards mitigation approaches and techniques indicates that significant advances have been made in hazards assessment, volcano monitoring, and eruption forecasting. For example, the remarkable accuracy of the predictions of dome-building events at Mount St. Helens since June 1980 is unprecedented. Yet a predictive capability for more voluminous and explosive eruptions still has not been achieved. Studies of magma-induced seismicity and ground deformation continue to provide the most systematic and reliable data for early detection of precursors to eruptions and shallow intrusions. In addition, some other geophysical monitoring techniques and geochemical methods have been refined and are being more widely applied and tested. Comparison of the four major volcanic disasters of the 1980s (Mount St. Helens, U.S.A. (1980), El Chichón, Mexico (1982); Galunggung, Indonesia (1982); and Nevado del Ruíz, Colombia (1985) illustrates the importance of predisaster geoscience studies, volcanic hazards assessments, volcano monitoring, contingency planning, and effective communications between scientists and authorities. The death toll (>22,000) from the Ruíz catastrophe probably could have been greatly reduced; the reasons for the tragically ineffective implementation of evacuation measures are still unclear and puzzling in view of the fact that sufficient warnings were given. The most pressing problem in the mitigation of volcanic and associated hazards on a global scale is that most of the world's dangerous volcanoes are in densely populated countries that lack the economic and scientific resources or the political will to adequately study and monitor them. This problem afflicts both developed and developing countries, but it is especially acute for the latter. The greatest advances in volcanic hazards mitigation in the near future are most likely to be achieved by wider application of existing technology to poorly understood and studied volcanoes, rather than by refinements or new discoveries in technology alone.

Reviews of Geophysics↗
USGS2014

Appendix C—Report on research in the field of ground water being conducted by oil companies

In view of the shortness of time since the appointment of the writer to the Committee on Ground Water this report is confined to the technology and problems in the Gulf Coast Oil Province. Of course, many of the methods and practices would apply to most parts of the country however, some would differ materially from one region to another. The writer wishes to acknowledge the suggestions and comments by F. H. LAHEE and PAUL WEAVER. Having been stationed in Houston, Texas, in the heart of the Gulf Coast Area for four and a half years, the writer has had an opportunity to view the great similarity of the problems confronting the petroleum geologist and engineer and the ground‐water hydrologist. Both groups deal with the accumulation, movement, and withdrawal of fluid from underground strata, yet each group is content to study its own literature and use its own terminology without much concern for the other. The petroleum and ground‐water engineer, independently of one another, have developed mathematical formulas for the determination of permeability from field‐data. These formulas use the same basic principles of physics and the initial papers on the subject by both groups were published within two years of one another. Because of the similarity in the technology and problems of the petroleum engineer and the ground‐water hydrologist there is a definite need for closer cooperation. Some of the problems are so closely related that their solution rests in cooperative studies.

Eos, Transactions, American Geophysical Union↗
USGS2017

Mineral supply for sustainable development requires resource governance

Successful delivery of the United Nations sustainable development goals and implementation of the Paris Agreement requires technologies that utilize a wide range of minerals in vast quantities. Metal recycling and technological change will contribute to sustaining supply, but mining must continue and grow for the foreseeable future to ensure that such minerals remain available to industry. New links are needed between existing institutional frameworks to oversee responsible sourcing of minerals, trajectories for mineral exploration, environmental practices, and consumer awareness of the effects of consumption. Here we present, through analysis of a comprehensive set of data and demand forecasts, an interdisciplinary perspective on how best to ensure ecologically viable continuity of global mineral supply over the coming decades.

Nature↗
USGS2020

Robotic environmental DNA bio-surveillance of freshwater health

Autonomous water sampling technologies may help to overcome the human resource challenges of monitoring biological threats to rivers over long time periods and large geographic areas. The Monterey Bay Aquarium Research Institute has pioneered a robotic Environmental Sample Processor (ESP) that overcomes some of the constraints associated with traditional sampling since it can automate water sample filtration and preservation of the captured material or homogenize it for immediate analyses in situ. The ESP was originally developed for marine environment applications. Here we evaluated whether the ESP can provide reliable, timely information on environmental (e)DNA detections of human and fish pathogens and introduced fishes at U.S. Geological Survey streamgage sites in freshwater rivers. We compared eDNA collected via ESP at high frequency (e.g., every 3 h) with manual eDNA collections collected at lower frequency (e.g., weekly). We found that water samples filtered and preserved by ESPs successfully detected the DNA of human pathogens, fish pathogens and introduced fishes. Both ESP and manually collected samples provided similar information about target DNA presence. We suggest that the greatest current benefit of the ESP is the cost savings of high frequency, bio-surveillance at remote or hard to access sites. The full potential of robotic technologies like the ESP will be realized when they can more easily execute in situ analyses of water samples and rapidly transmit results to decision-makers.

Idaho, Montana, Wyoming↗
USGS2023

Whole-lake acoustic telemetry to evaluate survival of stocked juvenile fish

Estimates of juvenile survival are critical for informing population dynamics and the ecology of fish, yet these demographic parameters are difficult to measure. Here, we demonstrate that advances in animal tracking technology provide opportunities to evaluate survival of juvenile tagged fish. We implemented a whole-lake telemetry array in conjunction with small acoustic tags (including tags < 1.0 g) to track the fate of stocked juvenile cisco ( Coregonus artedi ) as part of a native species restoration effort in the Finger Lakes region of New York, USA. We used time-to-event modeling to characterize the survival function of stocked fish, where we infer mortality as the cessation of tag detections. Survival estimates revealed distinct stages of juvenile cisco mortality including high immediate post-release mortality, followed by a period of elevated mortality during an acclimation period. By characterizing mortality over time, the whole-lake biotelemetry effort provided information useful for adapting stocking practices that may improve survival of stocked fish, and ultimately the success of the species reintroduction effort. The combination of acoustic technology and time-to-event modeling to inform fish survival may have wide applicability across waterbodies where receiver arrays can be deployed at scale and where basic assumptions about population closure can be satisfied.

New York↗
USGS2020

Gas hydrates in sustainable chemistry

Gas hydrates have received considerable attention due to their important role in flow assurance for the oil and gas industry, their extensive natural occurrence on Earth and extraterrestrial planets, and their significant applications in sustainable technologies including but not limited to gas and energy storage, gas separation, and water desalination. Given not only their inherent structural flexibility depending on the type of guest gas molecules and formation conditions, but also the synthetic effects of a wide range of chemical additives on their properties, these variabilities could be exploited to optimise the role of gas hydrates. This includes increasing their industrial applications, understanding and utilising their role in Nature, identifying potential methods for safely extracting natural gases stored in naturally occurring hydrates within the Earth, and for developing green technologies. This review summarizes the different properties of gas hydrates as well as their formation and dissociation kinetics and then reviews the fast-growing literature reporting their role and applications in the aforementioned fields, mainly concentrating on advances during the last decade. Challenges, limitations, and future perspectives of each field are briefly discussed. The overall objective of this review is to provide readers with an extensive overview of gas hydrates that we hope will stimulate further work on this riveting field.

Chemical Society Reviews↗
USGS1999

Applications and issues of GIS as tool for civil engineering modeling

A tool that has proliferated within civil engineering in recent years is geographic information systems (GIS). The goal of a tool is to supplement ability and knowledge that already exists, not to serve as a replacement for that which is lacking. To secure the benefits and avoid misuse of a burgeoning tool, engineers must understand the limitations, alternatives, and context of the tool. The common benefits of using GIS as a supplement to engineering modeling are summarized. Several brief case studies of GIS modeling applications are taken from popular civil engineering literature to demonstrate the wide use and varied implementation of GIS across the discipline. Drawing from the case studies, limitations regarding traditional GIS data models find the implementation of civil engineering models within current GIS are identified and countered by discussing the direction of the next generation of GIS. The paper concludes by highlighting the potential for the misuse of GIS in the context of engineering modeling and suggests that this potential can be reduced through education and awareness. The goal of this paper is to promote awareness of the issues related to GIS-based modeling and to assist in the formulation of questions regarding the application of current GIS. The technology has experienced much publicity of late, with many engineers being perhaps too excited about the usefulness of current GIS. An undoubtedly beneficial side effect of this, however, is that engineers are becoming more aware of GIS and, hopefully, the associated subtleties. Civil engineers must stay informed of GIS issues and progress, but more importantly, civil engineers must inform the GIS community to direct the technology development optimally.

Journal of Computing in Civil Engineering↗
USGS2012

A multi-disciplinary approach to the removal of emerging contaminants in municipal wastewater treatment plans in New York State, 2003-2004

Across the United States, there is a rapidly growing awareness of the occurrence and the toxicological impacts of natural and synthetic trace compounds in the environment. These trace compounds, referred to as emerging contaminants (ECs), are reported to cause a range of negative impacts in the environment, such as adverse effects on biota in receiving streams and interference with the normal functions of the endocrine system, which controls growth and development in living organisms. Wastewater treatment plants (WWTPs) have been identified as a key collection point for ECs in the water cycle and potentially an ideal location at which to treat to remove them, thereby mitigating their release into the environment ( Figure 1 ). This presents wastewater industry professionals with both a significant opportunity and a tremendous challenge: to identify cost effective treatment processes that can remove or reduce these contaminants before they are released into the environment. Although WWTPs have been identified as strategic focal points and potential treatment locations for the removal of ECs from the environment, little is known about the nature, variability, transport and fate of this class of compounds in typical wastewaters and treatment facilities in the United States. Furthermore few studies have been performed to monitor or understand the capability of conventional or innovative wastewater treatment processes to remove or reduce the concentrations of a wide variety of ECs at wastewater facilities. This study was designed to provide baseline information on this topic. While other studies have examined the occurrence of a limited number of representative contaminants in the environment (generally five to 10 compounds), this study is unique in that it provides information on a comprehensive list of ECs (63 ECs in total, Contaminant List in Appendix A, not included here) in the wastewater collection and treatment systems for four diverse communities over a two-year period. (It should be noted that the study is ongoing and additional data are pending but only 18 months of data are presented in this paper). The study was conducted in two phases. Phase 1 was designed to provide information concerning the general character and concentration of ECs commonly detected in wastewaters, the variability over a prolonged period of time, the transport and fate of ECs through typical wastewater treatment plants operating with a range of conventional technologies and the impact of WWTP discharges on receiving streams. It also provided guidance in understanding the capability of distinct wastewater treatment processes or technologies to reduce or remove ECs. The second phase of the study focused on one of the most common wastewater treatment processes operated in the United States, the Activated Sludge process. Using four controlled parallel activated sludge pilots, a more detailed assessment of the impact of Sludge Retention Time (SRT) on the reduction or removal of ECs was performed.

New York↗
USGS2022

Can non-invasive methods replace radiocollar-based winter counts in a 50-year wolf study? Lessons learned from a three-winter trial

Context: Monitoring low-density, elusive predators such as grey wolves ( Canis lupus ) has often been undertaken via live-capture and radio-collaring. Recent advances in non-invasive methods suggest live-captures may not be necessary for adequate monitoring. Further, non-invasive methods are considered best practice when possible. Aims: I evaluated whether a suite of non-invasive methods could replace aerial radiotelemetry to census resident pack wolves. Methods: I employed aerial snow-tracking, ground snow-tracking, camera-trapping, non-invasive genetic surveys, and community-scientist reports during three winters (2019–2021) in north-eastern Minnesota, USA to census pack wolves in a 2060 km 2 area. I attempted to enumerate individual pack sizes as has been historically undertaken to compile the census. Traditional aerial radiotelemetry methods were also conducted for comparison. Key results: Ground snow-tracking and camera-trapping provided the most similar information to radiotelemetry for determining pack counts and territory information, and, in some cases, documented higher pack counts than those obtained by aerial radiotelemetry. Radiotelemetry was the best method for determining pack territories, but was limited to radioed packs. A staggered application of both approaches resulted in increased precision and additional pack-level information without greatly increasing overall field effort. Non-invasive methods allowed trapping for radio-collaring to be reduced to every other year (a 50% reduction), but depending on trapping success, survival of animals, and radio-collar battery life, might even be reduced to every third year. Conclusions: In this 3-year trial, non-invasive methods were not sufficient to completely replace radio-collaring. Nevertheless, non-invasive methods allowed for a 50% reduction in trapping, increased the annual wolf-count precision, and increased community involvement. Anticipated technological improvements in non-invasive methods should reduce some issues encountered – but others will likely persist, in part, because of the fundamental nature of non-invasive methods. Implications: Less reliance on captures, enhanced pack information, and increased public involvement are all successful outcomes of this 3-year trial of non-invasive methods for monitoring wolf populations. Non-invasive methods continue to broaden and improve technologically, and information from trials such as this will help guide others as they increasingly implement non-invasive methods as partial or complete replacements for traditional capture-based methods.

Wildlife Research↗
USGS2005

Producing ammonium sulfate from flue gas desulfurization by-products

Emission control technologies using flue gas desulfurization (FGD) have been widely adopted by utilities burning high-sulfur fuels. However, these technologies require additional equipment, greater operating expenses, and increased costs for landfill disposal of the solid by-products produced. The financial burdens would be reduced if successful high-volume commercial applications of the FGD solid by-products were developed. In this study, the technical feasibility of producing ammonium sulfate from FGD residues by allowing it to react with ammonium carbonate in an aqueous solution was preliminarily assessed. Reaction temperatures of 60, 70, and 80??C and residence times of 4 and 6 hours were tested to determine the optimal conversion condition and final product evaluations. High yields (up to 83%) of ammonium sulfate with up to 99% purity were achieved under relatively mild conditions. The optimal conversion condition was observed at 60??C and a 4-hour residence time. The results of this study indicate the technical feasibility of producing ammonium sulfate fertilizer from an FGD by-product. Copyright ?? Taylor & Francis Inc.

Energy Sources↗
USGS2014

Analysis of the impact of spatial resolution on land/water classifications using high-resolution aerial imagery

Long-term monitoring efforts often use remote sensing to track trends in habitat or landscape conditions over time. To most appropriately compare observations over time, long-term monitoring efforts strive for consistency in methods. Thus, advances and changes in technology over time can present a challenge. For instance, modern camera technology has led to an increasing availability of very high-resolution imagery (i.e. submetre and metre) and a shift from analogue to digital photography. While numerous studies have shown that image resolution can impact the accuracy of classifications, most of these studies have focused on the impacts of comparing spatial resolution changes greater than 2 m. Thus, a knowledge gap exists on the impacts of minor changes in spatial resolution (i.e. submetre to about 1.5 m) in very high-resolution aerial imagery (i.e. 2 m resolution or less). This study compared the impact of spatial resolution on land/water classifications of an area dominated by coastal marsh vegetation in Louisiana, USA, using 1:12,000 scale colour-infrared analogue aerial photography (AAP) scanned at four different dot-per-inch resolutions simulating ground sample distances (GSDs) of 0.33, 0.54, 1, and 2 m. Analysis of the impact of spatial resolution on land/water classifications was conducted by exploring various spatial aspects of the classifications including density of waterbodies and frequency distributions in waterbody sizes. This study found that a small-magnitude change (1–1.5 m) in spatial resolution had little to no impact on the amount of water classified (i.e. percentage mapped was less than 1.5%), but had a significant impact on the mapping of very small waterbodies (i.e. waterbodies ≤ 250 m 2 ). These findings should interest those using temporal image classifications derived from very high-resolution aerial photography as a component of long-term monitoring programs.

Louisiana↗
USGS2015

Response of Bighead Carp and Silver Carp to repeated water gun operation in an enclosed shallow pond

The Bighead Carp Hypophthalmichthys nobilis and Silver Carp H. molitrix are nonnative species that pose a threat to Great Lakes ecosystems should they advance into those areas. Thus, technologies to impede Asian carp movement into the Great Lakes are needed; one potential technology is the seismic water gun. We evaluated the efficacy of a water gun array as a behavioral deterrent to the movement of acoustic-tagged Bighead Carp and Silver Carp in an experimental pond. Behavioral responses were evaluated by using four metrics: (1) fish distance from the water guns ( D ); (2) spatial area of the fish's utilization distribution (UD); (3) persistence velocity ( V p ); and (4) number of times a fish transited the water gun array. For both species, average D increased by 10 m during the firing period relative to the pre-firing period. During the firing period, the spatial area of use within the pond decreased. Carp were located throughout the pond during the pre-firing period but were concentrated in the north end of the pond during the firing period, thus reducing their UDs by roughly 50%. Overall, V p decreased during the firing period relative to the pre-firing period, as fish movement became more tortuous and confined, suggesting that the firing of the guns elicited a change in carp behavior. The water gun array was partially successful at impeding carp movement, but some fish did transit the array. Bighead Carp moved past the guns a total of 78 times during the pre-firing period and 15 times during the firing period; Silver Carp moved past the guns 96 times during the pre-firing period and 13 times during the firing period. Although the water guns did alter carp behavior, causing the fish to move away from the guns, this method was not 100% effective as a passage deterrent.

North American Journal of Fisheries Management↗